I've got a 93 rx7 R1 in a middle of a full rebuild. I receintly upgraded to a Koyo radiator and need to replace the AST. Should I go with factory or aftermarket? If aftermarket, which one. Is there any other cooling syst. upgrades I should consider while the car is all apart. The car has 96k on it and had set for 2 years. Don't know what condition the waterpump is in. It will turn with very little noise but has a little play in it.

the factory has a tendency to split at the seams..get an aftermarket one..

pettit comes to mind

I put the SARD AST on. Cheap and also it has an extra air bleed which you can put anywhere on your engine to help keep temps down. I chose to stick a air bleed on my lower RAD hose and have it connect to the AST. Along with another mod you will see here.



My own special mod

http://www.jt-imports.com/DSCF0337.JPG



Hose set-up (crappy shot)

http://www.jt-imports.com/DSCF0333.JPG

Pettit AST is popular. Some Japanese tuners also sell AST's for more $$. Check out sponsors' links above.



other cooling: upgrade intercooler, fan mod., downpipe...but basically you want to check your fluids often and let your car cool down after driving it hard before turning the engine off. https://www.nopistons.com/forums/pub...IR#>/smile.png

Works great. Before I did my little mod it was a pain to air bleed after after servicing it. My AST was free actually and run from $30-$90 USED and NEW from $50-$250 shipped.



I did my litttle mod with the earls line and fittings, VERY NICE!! Temps dropped about 2-4 C degrees.

i have the asi billet ast. it comes polished.

I looked at the asi billet ast. It looks good for the price. Thanks for the help.

i have a pettit works great

As for other upgrades, I like the Evans coolant. I put it in my car last fall, am interested in seeing how my temps change this summer. Mostly what I liked about it is that I can run 0 psi in the cooling system. That will be much easier on all the hoses and various seals and the AST. And if something does break instead of spraying coolant everywhere it will be more of a slower leak. Too bad the stuff is so expensive, at least it is good pretty much forever.